class A:
    def func1(self):
        print('A,func1')
class B :
    def func2(self):
        print('B func2')

    def func4(self):
        print('B 4')


class C(B, A):
    def func3(self):
        print('C func3')


if __name__ == '__main__':
    c1 = C()
    c1.func1()
    c1.func2()
    c1.func3()
    c1.func4()